 # JavaScript: Replace the first digit in a string (should contains at least digit) with \$ character

## JavaScript Basic: Exercise-136 with Solution

Write a JavaScript program to replace the first digit in a string (should contains at least digit) with \$ character.

Pictorial Presentation: Sample Solution:

HTML Code:

``````<!DOCTYPE html>
<html>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Replace the first digit in a string (should contains at least digit) with \$ character</title>
<body>

</body>
</html>
```
```

JavaScript Code:

``````function replace_first_digit(input_str) {

return input_str.replace(/[0-9]/, '\$');
}
console.log(replace_first_digit("abc1dabc"));
console.log(replace_first_digit("p3ython"));
console.log(replace_first_digit("ab1cabc"));
``````

Sample Output:

```abc\$dabc
p\$ython
ab\$cabc
```

Flowchart: ES6 Version:

``````function replace_first_digit(input_str) {

return input_str.replace(/[0-9]/, '\$');
}
console.log(replace_first_digit("abc1dabc"));
console.log(replace_first_digit("p3ython"));
console.log(replace_first_digit("ab1cabc"));
``````

Live Demo:

See the Pen javascript-basic-exercise-136 by w3resource (@w3resource) on CodePen.

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## JavaScript: Tips of the Day

Classes/function constructors

```class Person {
constructor() {
this.name = 'Owen';
}
}

Person = class AnotherPerson {
constructor() {
this.name = 'Eddie';
}
};

const member = new Person();
console.log(member.name);
```

We can set classes equal to other classes/function constructors. In this case, we set Person equal to AnotherPerson. The name on this constructor is Eddie, so the name property on the new Person instance member is "Eddie".

Ref: https://bit.ly/3jFRBje